Anyone who hasn't read it already should go pick up Thomas Friedman's The World is Flat.
You have NO competitive advantage. Anything you can do today, we can all replicate tomorrow. This is the problem with vivostock that they never saw coming. The world is flat - I can compete with istock - successfully or not - out of my basement.
Good book - suggested reading for this topic.
yes and no.
take an agency like REX Features for instance, it's the only one providing exclusive images of half of hollywood and half of the music industry.
their competitors are simply cut out of the loop as REX has plenty of exclusive material, old and new.
photo exclusivity is like champagne : it only grows in a small region of France, no matterif you try growing it elsewhere, it will taste like sh-it.